Architect

"Here I have some plans for the prototypes of new building levels! If you let me experiment a little, I'll help you to upgrade your buildings. For free! But decide now because I never stay in one place for long."

The architect is an event that appears randomly (every 10 days or so), showing up outside your castle in a camp called the Architect's pavilion. It lasts for a short amount of time (1-12 hours, depending on when you see it).

The highest levels for certain buildings can built only during the architect event, for no cost. These include:

Upgrading a building with the Architect is done the same way as upgrading any other building at any other time -- simply by selecting the building and choosing to upgrade it, rather than by talking to the Architect. It requires that you have an available construction slot, just as usual. If you do not have one available, you will not be able to use the Architect. While the Architect himself does not charge anything for access to these maximum building levels, you will still need the wood and stone to upgrade as normal.